This invention is directed to a shelf for refrigerators, though it is equally applicable for utilization as a book shelf or a shelf associated with most any type of furniture utilizing a cantilevered shelf.
Shelves specifically designed for refrigerators are well known, and typical thereof are the various shelves disclosed in U.S. Pat. No. 5,524,981 granted on Jun. 11, 1996 to Robert S. Herrmann et al. Each of the shelves of this patent include a cantilevered shelf which is defined by a glass panel and a peripheral frame defined by front and rear frame portions and opposite generally parallel side portions each having spaced ribs which define a groove for receiving a flange of a sliding xe2x80x9ccrisperxe2x80x9d drawer. The side walls each include a projecting hook which are engaged in horizontally aligned openings of a refrigerator compartment. Horizontal ribs afford the frame a modicum of rigidity along the length of the side walls, but no provision is made for front or rear rigidity which can create torque forces sufficient to bend or break the relatively narrow and weak hooks, particularly when the shelf panel and/or the drawer are heavily loaded with products. This difficulty is exacerbated if a relatively heavy/full drawer is pulled forward to gain access to products therein which lengthens the moment arm of the shelf and exacerbates the load applied to the hooks causing damage/destruction thereof. The latter is particularly true when the entire frame is formed of a single piece of molded polymeric/copolymeric synthetic plastic material, such as that disclosed relative to FIGS. 1 and 2 of the latter patent
Reinforcement can be achieved by forming separate rail members and riveting these to the side members of the upper shelf, as shown in FIG. 3 of the latter patent, but though this affords reinforcement, it also increases the overall weight of the shelf and the cost of manufacture/fabrication/assembly thereof.
Additional reinforcement by utilizing metallic side hanger brackets, as is illustrated in FIG. 5a of this patent, creates a relatively sturdy and rigid shelf, though a plurality of separate components must be separately united, some by rivets and some by an integrally injection molded frame which results in slow productivity and high material and end product costs.
It is also conventional to utilize metal side shelf brackets which are united by pairs of parallel rods for rigidity and with the metal side shelf brackets having hooks for hooking into horizontally aligned openings. A slider or sliding shelf formed of a glass panel and an injection molded frame has opposite side walls which are contoured to slide upon rails of the side shelf brackets, much as the manner illustrated in FIG. 10 of the latter patent. If the shelf is not required to function as a slider, the peripheral injection molded frame can be utilized to integrally unite (through molding) the metal side brackets and associated hooks to a glass panel, much in the manner illustrated in FIGS. 1, 3 and 5 of the latter patent.
U.S. Pat. No. 5,454,638 granted on Oct. 3, 1995 to Kevin C. Bird et al. is another example of a shelf having metallic side hanger brackets which are united to a glass panel by an injection molded frame. In this case rigidity is afforded the shelf by double hooks at each of the side brackets which are connected to a horizontal shelf rail bridging vertical posts carrying vertically spaced openings. The overall structure is relatively rigid, but the cost of materials and production is quite high and approaches commercial unfeasibility.
Other patents which disclose variations similar to those just described are disclosed in U.S. Pat. No. 5,403,084 granted on Apr. 4, 1995 to Edmund J. Kane et al., U.S. Pat. No. 5,540,493 granted on Jul. 30, 1996 to Edmund J. Kane et al., U.S. Pat. No. 5,660,777 granted on Aug. 26, 1997 to Robert S. Herrmann et al., U.S. Pat. No. 5,564,809 granted on Oct. 15, 1996 to Edmund J. Kane et al., U.S. Pat. No. 5,705,113 granted on Jan. 6, 1998 to Edmund J. Kane et al., U.S. Pat. No. 5,441,338 granted on Aug. 15, 1995 to Edmund J. Kane et al., U.S. Pat. No. 5,735,589 granted on Apr. 7, 1998 to Robert S. Herrmann et al., and U.S. Pat. No. 5,738,880 granted on Apr. 14, 1998 to Edmund J. Kane et al.
All of the patents thus far described are owned by the assignee of the present invention, namely, Gemtron Corporation of Sweetwater, Tenn., USA, a manufacturer of shelving for many well known refrigerator manufacturers who themselves have patents directed to refrigerator shelves, such as U.S. Pat. No. 5,516,204 granted on May 14, 1996 to Scott A. Calvert et al. and assigned to General Electric Company; U.S. Pat. No. 4,936,641 granted on Jun. 26, 1990 to Marc R. Bussan and assigned to Whirlpool Corporation; U.S. Pat. No. 4,870,836 granted on Oct. 3, 1989 to John J. Pink and assigned to Amana Refrigeration, Inc. and others, such as U.S. Pat. Nos. 4,745,775; 5,188,246; 3,633,983; 5,340,209 and 4,736,997 granted respectively on May 24, 1988; Feb. 23, 1993; Jan. 11, 1972; Aug. 23, 1994; and Apr. 12, 1988.
These patents establish the substance of the state of the art in this field and over which the present disclosure is considered a novel and unobvious departure.
In keeping with the foregoing, a novel refrigerator shelf of the present invention is constructed so as to be readily manufactured from a minimum number of components, and in reality only a single component is utilized during manufacture, yet the refrigerator shelf is attractive, stable, rigid, resistant to torque deflection, and can be manufactured rapidly and relatively inexpensively while at the same time being comparatively lightweight when measured against conventional refrigerator shelves. Low cost, attractiveness, strength and adaptability are functional characteristics of the present refrigerator shelf which uniquely distinguish the same from any one or all of the prior art shelves heretofore disclosed.
The refrigerator shelf of the present invention is manufactured from a single piece or panel of glass and injection molding a continuous border thereabout with suspension hooks projecting rearwardly and serving as integral cantilever suspension hooks for the shelf. To this extent, the shelf corresponds to the upper shelf of the first-mentioned patent, but distinguishes thereover in two important and specific features, namely, (1) at a minimum a pair of spaced side frame portions of the frame are each defined by inner and outer substantially spaced walls projecting below a lower surface of the glass shelf panel and between which span a plurality of reinforcing ribs, and (2) the suspension or cantilever hooks are relatively broad and each is provided with at least two vertically disposed substantially parallel spaced reinforcing ribs. The latter two structural features create a refrigerator shelf of extremely low cost, high aesthetics and increased strength including high resistance to torque and heavy product loading.
In further accordance with this invention, front and rear frame portions are likewise constructed from inner and outer substantially parallel spaced walls with reinforcing ribs spanning therebetween which particularly aid in resisting cocking or torquing of the refrigerator shelf.
In addition to the foregoing structural features of the invention, another important feature is that of locating the inner walls of at least the side frame portions beneath and inboard of a peripheral edge of the glass shelf panel which assures underlying peripheral support of the entire glass shelf panel affording maximum strength to the shelf, as well as resistance to cantilevered overloading, torquing or cocking thereof.